Rocking arm circular saws are known in the art, as evidenced by U.S. Pat. No. 4,336,733 issued June 29, 1982, to Macksoud. The saw shown in this prior patent is of a bench or tabletop type construction which allows both cross-cutting and ripping operations to be performed. The circular saw blade and associated driving motor therefor are both mounted on a rocking arm which is pivotally supported on the base of the saw, beneath a tabletop-like, horizontal surface which supports the workpiece to be cut. A generally U-shaped handle connected to the rocking arm assembly extends above the tabletop and provides the saw operator with a handle for rocking the saw blade from a lowered, retracted position beneath the tabletop to a raised cutting position in which at least a portion of the blade extends through a slot in the tabletop, above the tabletop surface. Cross-cutting operations are performed by maintaining the workpiece stationary on the tabletop and rocking the saw blade from its lowered retracted position to its raised cutting position, thereby pulling the blade through the workpiece to effect the cut.
Although the rocking arm saw described above is highly effective in operation and simple to use it has guiding means lacking versatility in guiding a workpiece to be cut at an angle different than 90.degree. degrees, the guiding means used on this machine is simply a single bar set on the tabletop for guiding at 90.degree. degres while the cross-cutting operations of this machine require guiding for cutting at many different angles.
On the other hand some tablesaws and like cutting machines including a cutting blade movable along a cutting line for cutting a workpiece held stable on the tabletop have guiding arrangements relatively costly when cutting little workpieces at different angles during continuous work, the same as turning and returning a heavy tabletop of a machine or turning and returning a heavy arm carrying a saw assembly and its driving motor for doing a little cut that may take no more than a second of cutting duration.
Therefore the guiding device of the present invention includes two guiding bars, one bar is constantly stable on the tabletop for guiding a workpiece to be cut at 90.degree. degrees and the other bar is pivotally adjustable on the tabletop with respect to the cutting line of the blade for guiding a workpiece to be cut at any of a plurality of angles.
The operator of the machine may have both guiding bars of the device adjacent each other on the tabletop as one bar set for guiding at an angle of 90.degree. degrees for better use of the tabletop when there is no cutting at other angles required, or he may use one bar for guiding at an angle of 90.degree. degrees and the other bar for guiding at another selected angle at the same time because no one bar of the device disturbs the other bar setting or guiding.
However, it is a primary object of the invention to provide a guiding device for a rocking arm saw capable of solving the guiding problems in its cross-cutting operations while at the same time, consideration must be given to the ease and portability of the saw. The saw described in U.S. Pat. No. 4,336,733 mentioned above is lightweight, compact and may be quickly converted into a readily portable package, consequently it is necessary that the angle guiding device be compatible with the portability of the saw and the ease with which it may be set up and taken down.
Another object of the invention is to improve the guiding of power saws and cutting machines of the type described here above and to make their guiding much less costly.
Other objects of the invention will be made clear or become apparent during the course of the following descriptions.